Instruments have been used heretofore for removing small specimens from a patient's lungs for analysis to assist in the diagnosis of the patient's condition. An elongated flexible tube has been inserted through the patient's throat and into the lung. A flexible push-pull element is operated from the inside of the tube. This push-pull element is operated from its upper end outside the patient. One or more brushes connected to the lower end of the push-pull element are movable by it between a retracted position inside the lower end of the tube and an extended position beyond the lower end of the tube for engaging and removing a specimen of the lung cell tissue and carrying it back into the tube when the push-pull element is retracted.
U.S. Pat. No. 2,739,585 shows such an arrangement having two wire brushes pivotally coupled to the lower end of the push-pull element. A spring biases these brushes apart when they are extended beyond the tube but permits them to move together when they are retracted into the tube.
Difficulties have been encountered with such insruments which use one or more brushes for removing the specimen because the brush itself is not always effective for this purpose. Also, the brush may be difficult to manufacture properly to serve its intended purpose.